Runway designs at airports range from single runways, to two or more parallel runways, to numerous runways facing different directions. For airports with two runways, one runway is typically used solely for takeoffs, while the second runway is used only for landings. If the airport has a single runway, the full length of the runway is used for either a takeoff or a landing (“dual/double mode”). Runway lengths differ depending on the size of the aircraft using the runway. Current designs are intended to accommodate and serve an ever-wider range of aircraft sizes including large wide-body heavy airliners such as the B-747, medium sized airliners such as the EMB-190, business jets, very light jets, and small single and multi-engine private aircraft.
Delayed Arrival and Departure Sequences
Airports world wide are experiencing increased gridlock and associated delays in aircraft arrivals and departures. Airports track the number and time between aircraft arrivals and departures on the runways as “arrival and departure sequences.” It is anticipated that air traffic will increase enormously during the coming decades, and with it, will come increased delays between the times aircraft can arrive and depart on the runways, causing delayed arrival and departure sequences. Increased air traffic causes aircraft in the air to be forced into holding patterns, while aircraft on the ground are forced to sit idle on the tarmac or slowly move in a takeoff queue. The delayed arrival and departure sequences directly lead to fuel cost increases, flight time increases, passenger ticket increases, and passenger dissatisfaction. With the increasing traffic comes an increasing need for safety and efficiency of traffic flow.
The detrimental financial impact of the delays is already being felt by the airlines. The United States Department of Transportation recently commenced subsidizing airlines for having to reduce their flight schedules in many of the United States' major airports due to overcrowding.
One approach to meeting the increased delays is through the construction of new, additional runways. The cost of constructing the necessary added runways is estimated to exceed a billion U.S. dollars. Moreover, the construction at many airports will not be possible given rising land costs and growing development around existing airports. Most airports are locked into expensive real estate with homes and businesses nestled on their borders. The land required for new runways is not available for many, if not most, airports.
Increased Risk of Accidents Caused by Runway Incursions and Air Vortices
Given the current and anticipated increase in air traffic world wide, there is a corresponding increase in the risk of airplane accidents caused by runway incursions and air vortices or wake turbulence. When an aircraft enters an active runway due to human and/or equipment error, the aircraft is at risk of causing a collision with another aircraft. Runway incursions are ranked and classed depending on how close the two aircraft come to actually colliding. To date, despite the development of various electronic methods for tracking airplanes while on the runways, no adequate method has been developed to prevent dangerous and potentially deadly runway incursions.
Another safety risk posed by current use of airport runways is takeoffs by smaller aircraft into dangerous air vortices formed by the wake of a preceding larger aircraft's takeoff. These potentially deadly wake turbulences are caused by use of the same runway for takeoffs of both large and small aircraft. In an attempt to address the problem, current FAA regulations require certain distances between aircraft takeoffs for “wake separation”. However, whenever a smaller aircraft takes off into the wake of a larger aircraft, there exists the concern for excessive turbulence. In addition, the distance requirements which are meant to render the takeoff safe add more wait time to the aircraft waiting for takeoff clearance.
Skyrocketing Jet Fuel Costs
With rising costs of jet fuel, airlines are in critical need of cutting costs through fuel conservation. Decreased delays in arrival and departure sequences, shorter taxiing times, and less idle waiting on the ground are essential to cutting fuel costs. However, with regard to takeoffs, to date, the size of the aircraft often dictates the type of clearance required (and idling time required) and also determines the taxiing distance to the end of the runway. The typical airliners of the T-category, such as the B-737, A-320 and those larger in size, are required to have dispatch clearance (prior authorization from a dispatcher for takeoff) and balanced runway lengths (a prescribed runway distance for takeoff to allow the aircraft to abort the takeoff if necessary) before taking off. As a result, the aircraft must be positioned at a point on the runway that allows sufficient runway for the aircraft to abort the takeoff if necessary. These factors add significant time, delay, and added fuel costs to the aircraft's operation.
With long lines, late flights, and near collisions, there is significant dissatisfaction with the U.S. air travel system, and the FAA is seemingly helpless to improve the system. FAA officials estimate that the overcrowded conditions will cost the American economy $22 billion annually within the next decade. Physically getting the airplanes out of the airports is becoming a serious problem, with some controllers reporting 4.5 mile long taxi lines at major airports.
Accordingly, there is a critical but as of yet un-met need in the art for an airport runway system using existing runways that increases the number and efficiency of aircraft arrival and departure sequences, that increases aircraft safety by both reducing the likelihood of aircraft runway incursions and reducing the likelihood of accidents caused by air vortices formed by larger aircraft, and which reduces taxiing and idle wait times to conserve jet fuel.